<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <meta http-equiv="X-UA-Compatible" content="ie=edge">
    <title>Document</title>
    <script
  src="https://code.jquery.com/jquery-2.2.4.min.js"
  integrity="sha256-BbhdlvQf/xTY9gja0Dq3HiwQF8LaCRTXxZKRutelT44="
  crossorigin="anonymous"></script>
    <style>
        .content{
            width:700px;
            height:400px;
            border:1px solid red;
        }
    </style>
</head>
<body>
    <h2>标题</h2>
    <div class="content">
        <iframe src="demo1.html" frameborder="0" width="700" height="400px"></iframe>
    </div>
</body>
</html>